The D-backs reached an agreement with free-agent pitcher

Bronson Arroyo on a two-year deal, with a club option that guarantees the right-hander $23.5 million, a club source has confirmed.

Arroyo will make $9.5 million in 2014 and '15, and the option for '16 is $11 million. If the D-backs decide not to pick up the option they will owe Arroyo a $4.5 million buyout.

Arroyo, who turns 37 later this month, was 14-12 with a 3.79 ERA last season for the Reds and has been a workhorse during his career. Over the last nine seasons, he has thrown at least 199 innings.

The D-backs were searching for a starting pitcher throughout the offseason. They explored trades for the Rays' David Price and the Cubs' Jeff Samardzija, and they were one of the finalists for the services of right-hander Masahiro Tanaka, who eventually signed a $155 million deal with the Yankees.

"It would be nice to have depth in that area," Towers said on Friday morning. "If the right guy is there that we think will create that depth and make us a better ballclub, we're going to look into it."

The signing pushes the D-backs' payroll over the $100 million mark for the first time since 2002.

With Arroyo in the fold, the D-backs' rotation appears to be set with Patrick Corbin, Arroyo, Wade Miley, Brandon McCarthy and Trevor Cahill.

That means that top prospect, Archie Bradley, who was expected to compete for the No. 5 spot in the rotation, will likely begin the year in the Minors.

Randall Delgado, who was also expected to compete for the rotation spot, might wind up being moved to the bullpen where the club thinks he could be even more effective than he was as a starter.

Arroyo was more attractive to the D-backs than other free-agent pitchers like Ervin Santana and Ubaldo Jimenez because unlike those two, the D-backs do not have to surrender their first-round pick in this year's First-Year Player Draft for signing him.

"First-round picks are pretty significant," Towers said. "I can't speak for the other 29 clubs, but it would take a special player for us to give up our first-round pick."

As it turns out, the D-backs added the pitcher they wanted and got to keep their pick.